Yes, that Harvey Milk. He had a long-term relationship with a frequent production manager on O'Horgan's work, J. Galen McKinley, who was like a son to Tom, and consequently Harvey occasionally pitched some money toward Tom's less commercial stuff. He was an associate producer on Inner City and Tom's assistant on both Hair and JCS long before he ever got into politics in California (in fact, he went to California in the first place partly because Galen accepted a position on the San Francisco production of Hair, and returned and stayed because he loved the area). There were more downs than ups to Harvey and Galen's relationship, and it was moving back to NY to help Tom on Superstar that led to their breakup.
Prior to that, the three of them had enjoyed a close friendship and worked together for several years. In fact, Tom's ashes were eventually scattered at the same spot in San Francisco Bay where Harvey's and Galen's remains had been scattered.
In fact, Harvey and Galen (the latter not mentioned by name) merit cameos in a New York Times Magazine profile of Tom from early 1972. (Ctrl+F is your friend when searching for specific mentions.)
.... and a bit more trivia: Tom O'Horgan had all 3 theaters on 47th St home to shows he directed. Along with INNER CITY, HAIR continued on at the Biltmore, and LENNY sat across the street at the Brooks Atkinson.
2016 These Paper Bullets (1/02) Our Mother's Brief Affair (1/06), Dragon Boat Racing (1/08), Howard - reading (1/28), Shear Madness (2/10), Fun Home (2/17), Women Without Men (2/18), Trip Of Love (2/21), The First Gentleman -reading (2/22), Southern Comfort (2/23), The Robber Bridegroom (2/24), She Loves Me (3/11), Shuffle Along (4/12), Shear Madness (4/14), Dear Evan Hansen (4/16), American Psycho (4/23), Tuck Everlasting (5/10), Indian Summer (5/15), Peer Gynt (5/18), Broadway's Rising Stars (7/11), Trip of Love (7/27), CATS (7/31), The Layover (8/17), An Act Of God (8/31), The Curious Incident of the Dog in the Night-Time (8/24), Heisenberg (10/12), Fiddler On The Roof (11/02), Othello (11/23), Dear Evan Hansen (11/26), Les Liaisons Dangereuses (12/21) 2017 In Transit (2/01), Groundhog Day (4/04), Ring Twice For Miranda (4/07), Church And State (4/10), The Lucky One (4/19), Ernest Shackleton Loves Me (5/16), Building The Wall (5/19), Indecent (6/01), Six Degrees of Separation (6/09), Marvin's Room (6/28), A Doll's House Pt 2 (7/25) Curvy Widow (8/01)
To get slightly more on topic, I think it's a little precious calling this a reunion concert when it boasts one -- count it, one -- member of the OBC, but it's great that 54 Below is devoting its attention to scores that never got a second chance.